E2E fixes (#8980)

* update dev-env

* hide nux after onboarding

* use getter/setter for proxy header

__e2e__/flows/onboarding-avatar-creator.yml

@@ -33,4 +33,9 @@ appId: xyz.blueskyweb.app
 - assertVisible: "You're ready to go!"
 - tapOn:
     id: "onboardingFinish"
+- tapOn:
+    label: "NUX, if applicable"
+    text: "Close"
+    optional: true
+- waitForAnimationToEnd
 - assertVisible: "Following"

__e2e__/flows/onboarding.yml

@@ -30,4 +30,9 @@ appId: xyz.blueskyweb.app
 - assertVisible: "You're ready to go!"
 - tapOn:
     id: "onboardingFinish"
+- tapOn:
+    label: "NUX, if applicable"
+    text: "Close"
+    optional: true
+- waitForAnimationToEnd
 - assertVisible: "Following"